1. Field of the Invention
The present invention relates to a rolling mill train. The invention particularly relates to a rolling mill train in a section mill with at least one group of rolling mill stands including n stands in a group. The rolling mill stands have at least horizontal guide members which are arranged at least on the middle stands spaced closely together in the pitch line.
The present invention also relates to a method for controlling the exchange of the stands in the above-described rolling mill train.
2. Description of the Related Art
The overall technical design of the combined section mills is important for the economical operation of the rolling mill and for the efficient manufacture of section steel of different shapes and sized. Substantially mechanized changing systems for rolling mill stands, rolls and guide members for the rolling mill stands are of particular importance for a cost-effective adjustment of the rolling mill train to different rolling schedules with different lot sizes.
In order to make it possible to utilize a rolling mill train for periods which are as long as possible, it has already been proposed to displace complete mill stands by means of manipulators or sliding platforms and snatch-type couplings from the rolling mill train onto separate sites and to replace the rolling mill stands by a rolling mill stand which has been adapted to the respective rolling schedule. The replacement rolling mill stand can be prepared on the separate site and can be moved into the rolling mill train by means of the manipulator. The use of replacement stands further makes it possible to arrange any chosen rolling systems one behind the other.
The above-described features provide the possibility of changing from one universal schedule to another or from a universal rolling mill operation to a two-high rolling operation or vice-versa. The time required for a quick change in schedules was substantially reduced. However, the replacement stands have the disadvantage that they require high investments and that many couplings are required which are medium-operated or electrically operated and are susceptible to trouble.
It is further known from European patent 2047 to move even heavy rolling mill stands quickly and in a structurally simple manner over long displacement distances during the exchange of stands. For this purpose, the rolling mill stand has its own drive which is operationally connected to rollers on which the stand can be moved along tracks directly into the pitch line or out of the pitch line.
For adjusting the rolling mill stands to different rolling schedules, it is also known to move complete sets of rolls transversely of the rolling line out of the rolling mill stands which are arranged stationary in the rolling mill stand. For this purpose, the guide members guiding the rolling material are disassembled. This is done by means of overhead trains or auxiliary trains. However, the disassembly, the assemly and the alignment of the guide members is very time-consuming and labor intensive. The reason for this is that the access to guide members is very difficult because of the narrow space available.
Therefore, the primary object of the present invention is to provide a rolling mill train of the above-described type in which the adjustment to different rolling schedules can be carried out more efficiently than in the past. This is to be achieved primarily by a substantial mechanization of the exchange of rolls and of guide members of the rolling mill stand, so that the time and personnel required for the change are reduced. In addition, the potential danger to the personnel during the roll change is to be reduced and the number of replacement stands is to be reduced.